The biomechanical, morphologic, and histochemical properties of the costal cartilages in children with pectus excavatum

Pectus excavatum. Surgical treatment: Structural or aesthetic?

INTRODUCTION

Pectus excavatum is a wall deformity that often warrants medical evaluation. In most cases, it's a purely visual aesthetic alteration, while in others, it comes with symptoms. Several surgical techniques have been described, but their outcomes are difficult to assess due to the heterogeneity of presentations and the lack of long-term follow-up. We present our experience as thoracic surgeons, assessing correction as either structural (remodeling of the thoracic cage through open surgery) or aesthetic (design and implantation of a customized 3D prosthesis).

MATERIAL AND METHODS

Retrospective observational study of the indication for surgical treatment of pectus excavatum carried out by a team of thoracic surgeons and the short- to mid-term results.

RESULTS

Between 2021 and 2023, we treated 36 cases surgically, either through thoracic cage remodeling techniques or with 3D prostheses. There were few minor complications, and the short- to mid-term results were positive: alleviation of symptoms or compression of structures when present, or aesthetic correction of the defect in other cases.

CONCLUSIONS

Surgery for pectus excavatum should be evaluated for structural correction of the wall or aesthetics. In the former, thoracic cage remodeling requiring cartilage excision and possibly osteotomies is necessary. In the latter, the defect is corrected with a customized 3D prosthesis.

Rapid fabrication and screening of tailored functional 3D biomaterials: Validation in bone tissue repair - Part II

Regenerative medicine strategies place increasingly sophisticated demands on 3D biomaterials to promote tissue formation at sites where tissue would otherwise not form. Ideally, the discovery/fabrication of the 3D scaffolds needs to be high-throughput and uniform to ensure quick and in-depth analysis in order to pinpoint appropriate chemical and mechanical properties of a biomaterial. Herein we present a versatile technique to screen new potential biocompatible acrylate-based 3D scaffolds with the ultimate aim of application in tissue repair. As part of this process, we identified an acrylate-based 3D porous scaffold that promoted cell proliferation followed by accelerated tissue formation, pre-requisites for tissue repair. Scaffolds were fabricated by a facile freeze-casting and an in-situ photo-polymerization route, embracing a high-throughput synthesis, screening and characterization protocol. The current studies demonstrate the dependence of cellular growth and vascularization on the porosity and intrinsic chemical nature of the scaffolds, with tuneable 3D scaffolds generated with large, interconnected pores suitable for cellular growth applied to skeletal reparation. Our studies showed increased cell proliferation, collagen and ALP expression, while chorioallantoic membrane assays indicated biocompatibility and demonstrated the angiogenic nature of the scaffolds. VEGRF2 expression in vivo observed throughout the 3D scaffolds in the absence of growth factor supplementation demonstrates a potential for angiogenesis. This novel platform provides an innovative approach to 3D scanning of synthetic biomaterials for tissue regeneration.

Patient-specific finite element modeling of scoliotic curve progression using region-specific stress-modulated vertebral growth

PURPOSE

This study describes the creation of patient-specific (PS) osteo-ligamentous finite element (FE) models of the spine, ribcage, and pelvis, simulation of up to three years of region-specific, stress-modulated growth, and validation of simulated curve progression with patient clinical angle measurements.

RESEARCH QUESTION

Does the inclusion of region-specific, stress-modulated vertebral growth, in addition to scaling based on age, weight, skeletal maturity, and spine flexibility allow for clinically accurate scoliotic curve progression prediction in patient-specific FE models of the spine, ribcage, and pelvis?

METHODS

Frontal, lateral, and lateral bending X-Rays of five AIS patients were obtained for approximately three-year timespans. PS-FE models were generated by morphing a normative template FE model with landmark points obtained from patient X-rays at the initial X-ray timepoint. Vertebral growth behavior and response to stress, as well as model material properties were made patient-specific based on several prognostic factors. Spine curvature angles from the PS-FE models were compared to the corresponding X-ray measurements.

RESULTS

Average FE model errors were 6.3 ± 4.6°, 12.2 ± 6.6°, 8.9 ± 7.7°, and 5.3 ± 3.4° for thoracic Cobb, lumbar Cobb, kyphosis, and lordosis angles, respectively. Average error in prediction of vertebral wedging at the apex and adjacent levels was 3.2 ± 2.2°. Vertebral column stress ranged from 0.11 MPa in tension to 0.79 MPa in compression.

CONCLUSION

Integration of region-specific stress-modulated growth, as well as adjustment of growth and material properties based on patient-specific data yielded clinically useful prediction accuracy while maintaining physiological stress magnitudes. This framework can be further developed for PS surgical simulation.

Nuss Technique for Pectus Excavatum in Adult Patients: Cosmetic Satisfaction and Improvement of Quality of Life in a Single-Center Experience

Objectives

Since its introduction, the Nuss minimally invasive procedure for pectus excavatum (PE) repair (MIRPE) has become the method of choice. The current study describes our experience of PE correction in adults, with particular focus on postoperative outcomes, pain, quality of life, and patients’ satisfaction.

Methods

We enrolled for this observational study n = 93 adult patients from 2011 to 2018. The Haller index was used to quantify PE severity. Pulmonary function tests and cardiac examinations were performed preoperatively; we developed a standardized surgical technique and postoperative treatment, including follow-up at 3, 12, and 24 months after surgery and 6 months after bar removal. We also evaluated the quality of life and the satisfaction with the cosmetic result after the procedure with standardized questionnaires.

Results

No operative or perioperative deaths occurred nor life-treating complications. Thirteen complications occurred in 12 patients, with a total complication rate of 14% (n = 13/93). Pain intensity decreased in the follow-up [pain score visual analog scale at 3 months: median 1 (0–8); 12 months: median 1 (0–5); and 24 months: median 1 (0–4)]. Better or much better quality of life after the Nuss procedure was observed: n = 79 (84.1%) at 3 months, n = 80 (86%) at 12 months, and n = 85 (91.4%) at 24 months. After 2 years of observation, more than 90% of patients described improvement in their quality of life and satisfaction with the cosmetic results. Only a very small group of patients suffered from pain in the follow-up.

Conclusion

Our results demonstrate that the MIRPE procedure is safe and can be performed with excellent results in adults both for improvement of quality of life and for satisfaction with cosmetic results.

Development of a Finite Element Model of the Pediatric Thoracic and Lumbar Spine, Ribcage, and Pelvis with Orthotropic Region-Specific Vertebral Growth

Finite element (FE) modeling of the spine has increasingly been applied in orthopedic precision-medicine approaches. Previously published FE models of the pediatric spine growth have made simplifications in geometry of anatomical structures, material properties, and representation of vertebral growth. To address those limitations, a comprehensive FE model of a pediatric (10-year-old) osteo-ligamentous thoracic and lumbar spine (T1-L5 with intervertebral discs (IVDs) and ligaments), ribcage, and pelvis with age- and level-specific ligament properties and orthotropic region-specific vertebral growth was developed and validated. Range of motion (ROM) measures, namely lateral bending, flexion-extension, and axial rotation, of the current 10 YO FE model were generally within reported ranges of scaled in vitro adult ROM data. Changes in T1-L5 spine height, as well as kyphosis (T2-T12) and lordosis (L1-L5) angles in the current FE model for two years of growth (from ages 10 to 12 years) were within ranges reported from corresponding pediatric clinical data. The use of such comprehensive pediatric FE models can provide clinically relevant insights into normative and pathological biomechanical responses of the spine, and also contribute to the development and optimization of clinical interventions for spine deformities.

Current Concepts in the Etiology and Pathogenesis of Pectus Excavatum in Humans-A Systematic Review

Pectus excavatum (PE) is the most common deformity of the chest wall and is characterized by the posterior depression of the sternum and the lower costal cartilages. To date, the etiology of PE in humans remains enigmatic. Several etiologic hypotheses have been proposed over the past two centuries. However, most of them have been scientifically dismissed and now have only historic value. In this systematic review, we assess scientific publications of the past two centuries addressing the issue of the origin of PE in humans. We present and discuss the histologic, genetic, biomechanical, and experimental scientific achievements that contributed to the clarification of its etiology and pathogenesis. With no clear consensus over the exact mechanism, most recent studies agree that the primordial defect leading the deformation of the anterior chest wall in PE is related to the costal hyaline cartilage structure and function. Further studies on this subject must be carried out. Genetic studies seem to be the most promising way to understand the exact mechanism of PE's origin and pathogenesis.

Costal cartilage overgrowth does not induce pectus‑like deformation in the chest wall of a rat model

Overgrowth of the costal cartilages has been frequently reported to be an etiological factor of chest wall deformities in children. The present study aimed to investigate if induced overgrowth of the costal cartilages could lead to deformation of the chest wall in a rat model. An insulin-like growth factor 1 (IGF1) solution was directly injected under the perichondrium of the last three costal cartilages of 2-week-old rat pups. Two different concentrations, 50 µg/ml (E50) and 100 µg/ml (E100), were applied. This procedure was repeated once per week for 5 consecutive weeks. Subsequently, 14 days after the last injection, all animals were euthanized before the shape of the thoracic cage was assessed, and the diameter was measured. In addition, the last three costal cartilages were dissected before the samples were prepared and examined by light microscopy. Rats that received E100 exhibited larger sagittal and coronal rib cage diameters compared with those in the E50 and control groups. However, no deformation could be observed in the chest wall. Microscopic examinations revealed an anabolic pattern in the E100 group. The present findings suggested that locally administered IGF1 stimulated cell proliferation and tissue growth in coastal cartilages in a dose-dependent manner in vivo. However, this induced overgrowth of the costal cartilages did not result in the deformation of the chest wall.

Anisotropic and age-dependent elastic material behavior of the human costal cartilage

Compared to articular cartilage, the biomechanical properties of costal cartilage have not yet been extensively explored. The research presented addresses this problem by studying for the first time the anisotropic elastic behavior of human costal cartilage. Samples were taken from 12 male and female cadavers and unconfined compression and indentation tests were performed in mediolateral and dorsoventral direction to determine Young’s Moduli E_C for compression and E_i5%, E_i10% and E_imax at 5%, 10% and maximum strain for indentation. Furthermore, the crack direction of the unconfined compression samples was determined and histological samples of the cartilage tissue were examined with the picrosirius-polarization staining method. The tests revealed mean Young’s Moduli of E_C = 32.9 ± 17.9 MPa (N = 10), E_i5% = 11.1 ± 5.6 MPa (N = 12), E_i10% = 13.3 ± 6.3 MPa (N = 12) and E_imax = 14.6 ± 6.6 MPa (N = 12). We found that the Young’s Moduli in the indentation test are clearly anisotropic with significant higher results in the mediolateral direction (all P = 0.002). In addition, a dependence of the crack direction of the compressed specimens on the load orientation was observed. Those findings were supported by the orientation of the structure of the collagen fibers determined in the histological examination. Also, a significant age-related elastic behavior of human costal cartilage could be shown with the unconfined compression test (P = 0.009) and the indentation test (P = 0.004), but no sex effect could be detected. Those results are helpful in the field of autologous grafts for rhinoplastic surgery and for the refinement of material parameters in Finite Element models e.g., for accident analyses with traumatic impact on the thorax.

Elastomeric Pain Pumps as an Adjunct for Postoperative Pain Control After Minimally Invasive Repair of Pectus Excavatum

Introduction: Pectus excavatum is a common congenital anomaly in the pediatric population. During the postoperative period, pain control is one of the top priorities. As a result, multiple techniques for pain control have been developed, including thoracic epidural analgesia, multimodal analgesia (MM), and elastomeric pain pump (EPP) placement. The purpose of this study was to evaluate the effectiveness of pain control using EPP as an adjunct to MM after the minimally invasive repair of pectus excavatum (MIRPE). Methods: We identified all pediatric patients undergoing MIRPE from June 2017 to July 2018. MM was employed in all patients; some patients additionally received subpleural EPP as adjuncts to postoperative analgesia. We reviewed pain scores, length of stay, opioid use, and complications. Results: During the study period, a total of 62 patients were included. The study cohort was divided into 15 patients undergoing MM alone versus 47 patients undergoing subpleural EPP placement plus MM (EPP + MM). Median pain scores were lower in the EPP + MM group (2.9 versus 4.2, P < .05). There was a significant reduction of total inpatient opioid use in the EPP + MM group (357.6 mg versus 466.9 mg, P = .03). There was no difference in median length of stay or complications. We found no significant difference between subpleural versus subcutaneous placement of the infusion catheters. Conclusion: The use of subpleural EPP as an adjunct to MM is an effective way to reduce pain and opioid use after MIRPE without increased risk of complications. Type of Study: Retrospective study with comparison group.

Rat Animal Model of Pectus Excavatum

Background: pectus excavatum (PE) is the most common congenital deformity of the thoracic wall. Lately, significant achievements have been made in finding new, less invasive treatment methods for PE. However, most of the experimental work was carried out without the help of an animal model. In this report we describe a method to create an animal model for PE in Sprague-Dawley rats. Methods: We selected 15 Sprague-Dawley rat pups and divided them into two groups: 10 for the experimental group (EG) and 5 for the control group (CG). We surgically resected the last four pairs of costal cartilages in rats from the EG. The animals were assessed by CT-scan prior to surgery and weekly for four consecutive weeks. After four weeks, the animals were euthanized and the thoracic cage was dissected from the surrounding tissue. Results: On the first postoperative CT, seven days after surgery, we observed a marked depression of the lower sternum in all animals from the EG. This deformity was present at every CT-scan after surgery and at the post-euthanasia assessment. Conclusions: By decreasing the structural strength of the lower costal cartilages, we produced a PE animal model in Sprague-Dawley rats.

Pectoralis Muscle Transposition in Association with the Ravitch Procedure in the Management of Severe Pectus Excavatum

Pectus excavatum (PE) is the most common congenital chest wall deformity. PE is sometimes associated with cardiorespiratory impairment, but is often associated with psychological distress, especially for patients in their teenage years. Surgical repair of pectus deformities has been shown to improve both physical limitations and psychosocial well-being in children. The most common surgical approaches for PE treatment are the modified Ravitch technique and the minimally invasive Nuss technique. A technical modification of the Ravitch procedure, which includes bilateral mobilization and midline transposition of the pectoralis muscle flap, is presented here.

Methods

From 2010 to 2016, 12 patients were treated by a modified Ravitch procedure with bilateral mobilization and midline transposition of the pectoralis muscle flap for severe PE. Outcomes, morphological results, and complications were analyzed with respect to this new combined surgical approach.

Results

There was a statistically significant difference between pre- and postoperative values (P = 0.0025) of the Haller index at the 18-month follow-up, showing a significant morphological improvement for all treated patients. After surgery, no morbidity and mortality were noted. The mean hospital stay was 7 days, and all patients were discharged without major complications.

Conclusion

This technique significantly improved patients' postoperative morphological outcomes and significantly reduced long-term complications, such as wound dehiscence, skin thinning, and hardware exposure.

Is Pectus Excavatum a Risk Factor for Spontaneous Pneumothorax? "Haller Index Measurements in Patients with Primary Spontaneous Pneumothorax"

Aim

In this study, we aimed to retrospectively investigate whether pectus excavatum (PE) is a risk factor for the development of primary spontaneous pneumothorax (PSP) and to determine its role in the etiology of the disease.

Materials and Methods

Chest-computed tomography (CT) of the patients who were treated for spontaneous pneumothorax between January 2015 and December 2017 in our clinic was examined, and their Haller indices were measured (group I). The patients in the control group who underwent chest CT for other reasons during the same period and were in the same age with the group I were also included in the study (group II) Results. In group I, for patients with PE, the mean Haller index was 2.41, while it was 2.09 in the control group (group II). There was a significant difference between the two groups.

Conclusions

PE deformities in the chest wall may predispose to the development of spontaneous pneumothorax, and PE may be among the etiologic factors of spontaneous pneumothorax. Therefore, there is a need for studies involving larger patient groups.

A Decade's Experience: A Sound Framework as the Foundation to Nasal Reconstruction

The goal of nasal reconstruction surgery is to restore normal nasal shape and function, and its success begins with creating a stable framework. In this article the authors discuss the most advantageous materials for building such a framework and how to design this element to achieve better and more durable outcomes. This is a retrospective study including patients who underwent nasal reconstruction in our rhinoplasty and nasal reconstruction center at a tertiary referral hospital between 2006 and 2016. Data included patient characteristics, defect location, the reason for defect, use of supporting structure, flap, lining, and complications were recorded. The minimum postoperative follow-up was at least 6 months after the last operation. This study included 455 patients. Nasal defects treated most commonly involved zone 2 and an average defect of 4.2 subunits. Expanded forehead flap for cover with costal cartilage as a framework and turn-over flap combined with distal end of the flap for lining was the most common reconstruction method used in this study. The complication rate was 4.39% and nearly half of these complications were related to usage of an expander during reconstruction. Regardless of flap used, the supporting structure was the most critical element for the 3-dimensional shape of the reconstructed nose. As 1 of the 3 elements of nasal reconstruction, framework deserves adequate attention during such reconstruction.

[Costal cartilage structural and functional changes in children with a funnel or keeled chest]

Congenital chest wall deformities (CCWDs) in children are severe diseases leading to cosmetic defects and diseases of the respiratory and cardiovascular systems. The most common of these deformities are funnel-shaped (pectus excavatum, FD) and keeled (pectus carinatum, KD) ones. The pathogenesis of CCWDs and the role of costal cartilage structural and functional changes in their pathogenesis have now been not well studied, which makes it difficult to elaborate pathogenetic approaches to correcting these diseases. Analysis of the literature has shown that structural and functional changes occur in the matrix and chondrocytes from the costal cartilage in FD. Similar costal cartilage changes are observed in KD. It is still unknown exactly which pathological processes are present in the costal cartilage and how they result in the development of one or other type of CCWDs. The role of amianthoid transformation (AT) of costal cartilages in these processes is also unknown. It is not improbable that it is AT drastically changing the native cartilage matrix, which is one of the key mechanisms leading to changes in its properties and to the subsequent development of FD or KD.

Occult RV systolic dysfunction detected by CMR derived RV circumferential strain in patients with pectus excavatum

Aims

To investigate the right ventricular (RV) strain in pectus excavatum (PE) patients using cardiac magnetic resonance tissue tracking (CMR TT).

Materials and methods

Fifty consecutive pectus excavatum patients, 10 to 32 years of age (mean age 15 ± 4 years), underwent routine cardiac magnetic resonance imaging (CMR) including standard measures of chest geometry and cardiac size and function. The control group consisted of 20 healthy patients with a mean age of 17 ± 5 years. RV longitudinal and circumferential strain magnitude was assessed by a dedicated RV tissue tracking software.

Results

Fifty patients with images of sufficient quality were included in the analysis. The mean right and left ventricular ejection fractions were 55 ± 5% and 59 ± 4%. The RV global longitudinal strain was -21.88 ± 4.63%. The RV circumferential strain at base, mid-cavity and apex were -13.66 ± 3.09%, -11.31 ± 2.79%, -20.73 ± 3.45%, respectively. There was no statistically significant decrease in right ventricular or left ventricular ejection fraction between patients and controls (p > 0.05 for each). There was no significant difference in RV global longitudinal strain between two groups (-21.88 ± 4.63 versus -21.99 ± 3.58; p = 0.93). However, there was significant decrease in mid-cavity circumferential strain magnitude in pectus patients compared with controls (-11.31 ± 2.79 versus -16.19 ± 2.86; p < 0.001). PE patients had a significantly higher basal circumferential strain (-13.66 ± 3.09% versus -9.76 ± 1.79; p < 0.001) as well as apical circumferential strain (-20.73 ± 3.45% versus -12.07 ± 3.38) than control group.

Conclusion

Mid-cavity circumferential strain but not longitudinal strain is reduced in pectus excavatum patients. Basal circumferential strain as well as apical circumferential strain were increased as compensatory mechanism for reduced mid-cavity circumferential strain. Further studies are needed to establish clinical significance of this finding.

Measurement of sternal curvature angle on patients with pectus excavatum

BACKGROUND

Pectus excavatum (PE) is a chest deformity characterized by marked sternal depression. The objective of this study was to quantify the sternal curvature observed in patients diagnosed with PE using the sternal curvature angle (SCA).

METHODS

A retrospective review of lateral chest X-rays of patients with PE from 2006 to 2013 was performed. The SCA was measured in a manner similar to the method of Cobb's angle is used to measure spinal curvature. SCA and Haller index were calculated from the chest X-rays for all patients.

RESULTS

Lateral chest X-rays of 202 PE and 196 normal control patients were analyzed. The mean SCA ± SD of PE patients was 40.56° ± 12.88° compared to 22.02° ± 7.65° for normal patients. The difference was statistically significant with a p value of <0.0001. No significant concordance between SCA and Haller index measurements in the PE group was found (Kendall τ = -0.00015, p value = 0.9975).

CONCLUSION

The difference in sternal curvature as measured by the sternal curvature angle between the pectus excavatum and normal patients was statistically significant. Our data suggest that sternal depression evident in PE patients is not a simple linear depression of the sternum but due to curvature in the sternal body.

Costal Cartilages Do Not Overgrow in Patients with Pectus Excavatum

OBJECTIVE

The purpose of this study was to determine whether or not patients with pectus excavatum (PE) exhibit costal cartilage overgrowth compared to normal subjects.

MATERIALS AND METHODS

The computed tomography acquisitions of 32 patients with PE and 35 normal controls were analyzed. On axial images the length of the 4th-7th costal cartilages was measured to calculate the Haller index. The ratio between the length of the cartilages and the median of the transverse and longitudinal thorax diameters were recorded to account for anatomical variability. The length of the cartilages was compared between the PE and control subjects using the independent-samples t test. For patients with asymmetric PE the length of the 4th-7th costal cartilages was compared between the rotated and nonrotated sides.

RESULTS

The mean transverse and coronal thorax diameters were 233.29 ± 24.47 and 231.69 ± 22.47 mm for PE patients and 252.67 ± 37.25 and 238.64 ± 27.40 mm for controls, respectively, with no significant differences between the two groups (p = 0.816 and 0.145). The mean sagittal diameter (59.30 ± 14.21 mm) and Haller index (4.02 ± 1.34) in the PE group were significantly different from the controls (107.34 ± 19.59 and 2.2 ± 0.54 mm, respectively; p = 0.00). Actual and relative lengths of costal cartilages were similar in both PE subjects and controls for all 4 costal cartilages measured. In subjects with asymmetric PE, both relative and absolute costal cartilage lengths were similar on the rotated and nonrotated side.

CONCLUSIONS

The length of the 4th, 5th, 6th and 7th costal cartilages was similar in PE patients and the control subjects. These was also similar between the rotated and nonrotated sides of the sternum in patients with asymmetric PE.

Comprehensive analysis of translational osteochondral repair: Focus on the histological assessment

Articular cartilage guarantees for an optimal functioning of diarthrodial joints by providing a gliding surface for smooth articulation, weight distribution, and shock absorbing while the subchondral bone plays a crucial role in its biomechanical and nutritive support. Both tissues together form the osteochondral unit. The structural assessment of the osteochondral unit is now considered the key standard procedure for evaluating articular cartilage repair in translational animal models. The aim of this review is to give a detailed overview of the different methods for a comprehensive evaluation of osteochondral repair. The main focus is on the histological assessment as the gold standard, together with immunohistochemistry, and polarized light microscopy. Additionally, standards of macroscopic, non-destructive imaging such as high resolution MRI and micro-CT, biochemical, and molecular biological evaluations are addressed. Potential pitfalls of analysis are outlined. A second focus is to suggest recommendations for osteochondral evaluation.

A study about the costoclavicular space in patients with pectus excavatum

Background

The aim of the present study is to investigate the costoclavicular space in patients with pectus excavatum.

Materials and methods

Between April and November 2011, consecutive 50 patients with pectus excavatum and consecutive 50 patients without pectus excavatum were included into the present study. The costoclavicular measurements (the shortest distance, the crossing angle) were measured for the costoclavicular investigation.

Results

Firstly, there were no significant differences of the costoclavicular measurements in each and between symmetric and asymmetric subgroup, and in the overall, bilaterally. The shortest distance had a significant positive correlation with BMI (right p = 0.001, left p = 0.032) and a significant negative correlation with the crossing angle (right p = 0.013, left p = 0.001). Secondly, in the control group, the shortest distance had significant positive correlations with body weight and BMI (Body weight right p = 0.001, left p < 0.001; BMI right p = 0.001, left p < 0.001), and significant negative correlations with the crossing angles (right p = 0.002, left p < 0.001) and the sternal angle (right p = 0.032, left p = 0.017). Thirdly, the control group had the significant longer shortest distance than the pectus excavatum group (right p <0.001, left p <0.001). Fourthly, a decrease of the shortest distance (right p <0.001, left p <0.001), an increase of the crossing angle (right p < 0.001, left p < 0.001) and the sternal angle (p <0.001), and also a decrease of the Haller index (p <0.001) was found postoperatively.

Conclusion

Patients with pectus excavatum originally have narrower costoclavicular spaces than the normal control group, and the postoperative costoclavicular space are much narrower also.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0189-2) contains supplementary material, which is available to authorized users.

Surgical interventions for treating pectus excavatum

BACKGROUND

Pectus excavatum is characterized by a depression of the anterior chest wall (sternum and lower costal cartilages) and is the most frequently occurring chest wall deformity. The prevalence ranges from 6.28 to 12 cases per 1000 around the world. Generally pectus excavatum is present at birth or is identified after a few weeks or months; however, sometimes it becomes evident only at puberty. The consequence of the condition on a individual's life is variable, some live a normal life and others have physical and psychological symptoms such as: precordial pain after exercises; impairments of pulmonary and cardiac function; shyness and social isolation. For many years, sub-perichondrial resection of the costal cartilages, with or without transverse cuneiform osteotomy of the sternum and placement of a substernal support, called conventional surgery, was the most accepted option for surgical repair of these patients. From 1997 a new surgical repair called, minimally invasive surgery, became available. This less invasive surgical option consists of the retrosternal placement of a curved metal bar, without resections of the costal cartilages or sternum osteotomy, and is performed by videothoracoscopy. However, many aspects that relate to the benefits and harms of both techniques have not been defined.

OBJECTIVES

To evaluate the effectiveness and safety of the conventional surgery compared with minimally invasive surgery for treating people with pectus excavatum.

SEARCH METHODS

With the aim of increasing the sensitivity of the search strategy we used only terms related to the individual's condition (pectus excavatum); terms related to the interventions, outcomes and types of studies were not included. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, LILACS, and ICTPR. Additionally we searched yet reference lists of articles and conference proceedings. All searches were done without language restriction.Date of the most recent searches: 14 January 2014.

SELECTION CRITERIA

We considered randomized or quasi-randomized controlled trials that compared traditional surgery with minimally invasive surgery for treating pectus excavatum.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of the trials identified and agreed trial eligibility after a consensus meeting. The authors also assessed the risk of bias of the eligible trials.

MAIN RESULTS

Initially we located 4111 trials from the electronic searches and two further trials from other resources. All trials were added into reference management software and the duplicates were excluded, leaving 2517 studies. The titles and abstracts of these 2517 studies were independently analyzed by two authors and finally eight trials were selected for full text analysis, after which they were all excluded, as they did not fulfil the inclusion criteria.

AUTHORS' CONCLUSIONS

There is no evidence from randomized controlled trials to conclude what is the best surgical option to treat people with pectus excavatum.

An intragenic deletion of the gene MNAT1 in a family with pectus deformities

Pectus carinatum and excavatum have multiple genetic associations. We report on a novel association of these deformities in a 34-month-old male and his father, likely due to a small intragenic deletion of MNAT1 (ménage a trois 1 gene). Both individuals share a deletion of MNAT1 located at 14q23.1 and an interstitial duplication of CHRNA7 located at 15q13.3. Deletion of MNAT1 has been associated with connective tissue abnormalities and is likely the etiology of the malformations, whereas the duplication of CHNRA7 is unlikely related due to the lack of association with any such connective tissue abnormalities.

Systematic review of surgical treatment techniques for adult and pediatric patients with pectus excavatum

This compares outcome measures of current pectus excavatum (PEx) treatments, namely the Nuss and Ravitch procedures, in pediatric and adult patients. Original investigations that stratified PEx patients based on current treatment and age (pediatric=0-21; adult 17-99) were considered for inclusion. Outcome measures were: operation duration, analgesia duration, blood loss, length of stay (LOS), outcome ratings, complications, and percentage requiring reoperations. Adult implant patients (18.8%) had higher reoperation rates than adult Nuss or Ravitch patients (5.3% and 3.3% respectively). Adult Nuss patients had longer LOS (7.3 days), more strut/bar displacement (6.1%), and more epidural analgesia (3 days) than adult Ravitch patients (2.9 days, 0%, 0 days). Excluding pectus bar and strut displacements, pediatric and adult Nuss patients tended to have higher complication rates (pediatric - 38%; adult - 21%) compared to pediatric and adult Ravitch patients (12.5%; 8%). Pediatric Ravitch patients clearly had more strut displacements than adult Ravitch patients (0% and 6.4% respectively). These results suggest significantly better results in common PEx surgical repair techniques (i.e. Nuss and Ravitch) than uncommon techniques (i.e. Implants and Robicsek). The results suggest slightly better outcomes in pediatric Nuss procedure patients as compared with all other groups. We recommend that symptomatic pediatric patients with uncomplicated PEx receive the Nuss procedure. We suggest that adult patients receive the Nuss or Ravitch procedure, even though the long-term complication rates of the adult Nuss procedure require more investigation.

Dependence of optical attenuation coefficient and mechanical tension of irradiated human cartilage measured by optical coherence tomography

As banked human tissues are not widely available, the development of new non-destructive and contactless techniques to evaluate the quality of allografts before distribution for transplantation is very important. Also, tissues will be processed accordingly to standard procedures and to minimize disease transmission most tissue banks will include a decontamination or sterilization step such as ionizing radiation. In this work, we present a new method to evaluate the internal structure of frozen or glycerol-processed human cartilages, submitted to various dosis of irradiation, using the total optical attenuation coefficient retrieved from optical coherence tomography (OCT) images. Our results show a close relationship between tensile properties and the total optical attenuation coefficient of cartilages. Therefore, OCT associated with the total optical attenuation coefficient open a new window to evaluate quantitatively biological changes in processed tissues.

Rib cartilage characterization in patients affected by pectus excavatum

Pectus excavatum (PE) is the most frequent anterior chest deformity which may be frequently associated with connective tissue disorders. We performed microscopic analyses to better understand cartilage behavior and obtain clues on its pathogenesis. In 37 PE patients, none with Marfan syndrome, we analyzed costal cartilage by light microscopy, immunohistochemistry and transmission electron microscopy. Control tissue specimens were harvested from four patients without any connective tissue disease. In both control and PE patients, chondrocytes were on the average <15 µm in diameter and occupied <10% of tissue volume; in most cases the extracellular matrix was stained by alcian blue, instead of safranin; no difference between PE and control samples was significant. All samples showed an uneven collagen type II immunolabeling both within the cells and pericellular matrix, and occasionally of the territorial matrix. In all cases numerous cells underwent apoptosis accompanied by matrix condensation as shown by electron microscopy. Our results suggest that matrix composition and the cell number and size of costal cartilage are dependent on the subject and not on the disease; the microscopic organization of cartilage is correlated with the stabilization of the defective shape rather than with the onset of the deformity.

Pectus excavatum and heritable disorders of the connective tissue

Pectus excavatum, the most frequent congenital chest wall deformity, may be rarely observed as a sole deformity or as a sign of an underlying connective tissue disorder. To date, only few studies have described correlations between this deformity and heritable connective tissue disorders such as Marfan, Ehlers-Danlos, Poland, MASS (Mitral valve prolapse, not progressive Aortic enlargement, Skeletal and Skin alterations) phenotype among others. When concurring with connective tissue disorder, cardiopulmonary and vascular involvement may be associated to the thoracic defect. Ruling out the concomitance of pectus excavatum and connective tissue disorders, therefore, may have a direct implication both on surgical outcome and long term prognosis. In this review we focused on biological bases of connective tissue disorders which may be relevant to the pathogenesis of pectus excavatum, portraying surgical and clinical implication of their concurrence.

Dependence of optical attenuation coefficient and mechanical tension of irradiated human cartilage measured by optical coherence tomography

As banked human tissues are not widely available, the development of new non-destructive and contactless techniques to evaluate the quality of allografts before distribution for transplantation is very important. Also, tissues will be processed accordingly to standard procedures and to minimize disease transmission most tissue banks will include a decontamination or sterilization step such as ionizing radiation. In this work, we present a new method to evaluate the internal structure of frozen or glycerol processed human cartilages, submitted to various dosis of irradiation, using the total optical attenuation coefficient retrieved from optical coherence tomography (OCT) images. Our results show a close relationship between tensile properties and the total optical attenuation coefficient of cartilages. Therefore, OCT associated with the total optical attenuation coefficient open a new window to evaluate quantitatively biological changes in processed tissues.

Modified Nuss procedure is a safe choice for recurrent pectus excavatum after previous open repair experience of 26 cases

PURPOSE

This study is aiming to investigate the feasibility and effect of applying modified Nuss procedure on recurrent pectus excavatum following previous open repair.

METHODS

By retrospectively reviewing patients of pectus excavatum enrolled in our department from July 2007 to August 2012, we find 27 cases of recurrent PE who received open repair previously. Twenty-six patients received Nuss repair, while one patient refused. Relevant data are collected and processed. A 3-month follow-up after operation is also reviewed. Analysis of data is conducted.

RESULTS

Twenty-six recurrent patients underwent modified Nuss procedure safely. Pneumothorax after operation occurred in one case. Pleural effusion occurred for every case, most were mild in quantity except two cases whose pleural effusion were moderate. All patients left hospital within 2 weeks after operation except one patient who died of respiration failure. Mean postoperative Haller Index is significantly different from the preoperative one. Cosmetic effect was excellent for 5 cases, good for 15 cases, moderate for 6 cases. In a 3-month follow-up, no bar displacement or rejection happened and pleural effusion was completely absorbed.

CONCLUSION

Although technically challenging, Nuss procedure is feasible and good for recurrent PE after open repair.

The role of transthoracic ultrasounds to assess patients with pectus excavatum

INTRODUCTION

Pectus excavatum is the most common congenital malformation of the anterior chest wall. The purpose of this study is to assess the role of thoracic ultrasound studies in the preoperative workup of patients affected by pectus excavatum and to identify the dynamics of the chest wall.

MATERIALS AND METHODS

An observational study was carried out between January and September 2011. Patients between 4 and 14 years of age were divided into 5 study groups. Group A: healthy patients without pectus excavatum; Group B: healthy patients with different grades of untreated pectus excavatum; Group C: patients with pectus excavatum treated with a Nuss bar; Group D: patients surgically treated with removed bar; Group E: patients surgically treated with different techniques.

RESULTS

Patients with deeper anatomical depression showed a differential value between maximum inspiration and forced expiration lower than healthy patients or patients with shallower depression (p<0.05) in any age range considered. A depression deeper than 2.8 cm was associated with lower elasticity of the chest wall.

CONCLUSIONS

Study results demonstrate that the ultrasound is useful in patients with PE. Patients with pectus excavatum have altered chest dynamics when compared to healthy patients. The study also demonstrate that between the 4th and the 6th ribs there is the great dynamicity of the chest wall.

Decorin expression, straw-like structure, and differentiation of human costal cartilage

Costal cartilage is much understudied compared with the load-bearing cartilages. Abnormally grown costal cartilages are associated with the inherited chest wall deformities pectus excavatum and pectus carinatum resulting in sunken and pigeon chests, respectively. A lack of understanding of the ultrastructural and molecular biology of costal cartilage is a major confounder in predicting causes and outcomes of these disorders. This study analyzed the structure of marginal human costal cartilage (ribs 6-10) through scanning electron and atomic force microscopes and identified the presence of straw-like structures running longitudinally. We also demonstrated that chondrocytes tend to occur singly or as doublets and that centrally located cells produce high levels of aggrecan compared with more peripherally located cells measured using immunohistochemistry. Gene expression from mRNA extracted from cartilage showed high levels of decorin expression, likely associated with the large, complex tubular structures running through this cartilage type. COL2A1, ACAN, and TIMP1 also showed higher levels of expression compared with ACTB. Analysis of gene expression ratios demonstrate that costal cartilage is under differentiated compared with published ratios for articular cartilage, likely due to the vastly different biomechanical environments of each cartilage type. Further studies need to establish whether findings described here from the costal margins are significantly different than the cartilage of the "true ribs" and how these values change with age.

Effects of ionizing radiation and preservation on biomechanical properties of human costal cartilage

Tissue banks around the world store human cartilage obtained from cadaveric donors for use in diverse reconstructive surgical procedures. To ensure this tissue is sterile at the time of distribution, tissues may be sterilized by ionizing radiation. In this work, we evaluate the physical changes in deep frozen costal cartilage (-70 °C) or costal cartilage preserved in high concentrations of glycerol (>98 %) followed by a terminal sterilization process using ionizing radiation, at 3 different doses (15, 25 and 50 kGy). Tension and compression tests were carried out to determine the mechanical changes related both to the different preservation methods and irradiation doses. For both methods of preservation, tension strength was increased by about 24 %, when cartilage tissue was irradiated with 15 kGy. Deep frozen samples, when irradiated with 25 or 50 kGy, had a decrease in their mechanical performance, albeit to a lesser extent than when tissues were preserved in high concentration of glycerol and equally irradiated. In conclusion, processing in high concentration of glycerol did not increase tissue protection against radiation damage; while cartilage preserved in high concentrations of glycerol withstands radiation up to 25 kGy, deep frozen human costal cartilage may be sterilized with a doses up to 50 kGy without significant mechanical impact.

Pectus excavatum: history, hypotheses and treatment options

Pectus excavatum and pectus carinatum represent the most frequent chest wall deformations. However, the pathogenesis is still poorly understood and research results remain inconsistent. To focus on the recent state of knowledge, we summarize and critically discuss the pathological concepts based on the history of these entities, beginning with the first description in the sixteenth century. Based on the early clinical descriptions, we review and discuss the different pathogenetic hypotheses. To open new perspectives for the potential pathomechanisms, the embryonic and foetal development of the ribs and the sternum is highlighted following the understanding that the origin of these deformities is given by the disruption in the maturation of the parasternal region. In the second, different therapeutical techniques are highlighted and based on the pathogenetic hypotheses and the embryological knowledge potential new biomaterial-based perspectives with interesting insights for tissue engineering-based treatment options are presented.

Chest fast MRI: an imaging alternative on pre-operative evaluation of Pectus Excavatum

BACKGROUND

Standard imaging methods in evaluating chest wall deformities, such as Pectus Excavatum (PE) in paediatric and adolescent patients, include baseline 2-view chest radiography and chest CT scan. Only few studies to date investigated the value of fast MRIin the pre operative assessment of patient affected by PE.

OBJECTIVE

To evaluate the efficacy of chest fast MRI in pre-operative management of patient affected by PE. To obtain the Haller Index (HI) and Asymmetry Index (AI) from chest fast MRI protecting patients from radiation exposure.

MATERIALS AND METHODS

We analyzed the data of 42 consecutive patients with severe PE who underwent minimally invasive repair between March 2007 and March 2010. All 42 patients received chest fast MRI, but only the first 5 in view of the results, were studied also with chest ultrafast CT scan. In both examinations, data at the deepest point of the depression were collected.

RESULTS

Severity indices of the deformity using HI and AI, collected from CT scan and fast MRI in the first 5 patients, were comparable. In the remaining 37 fast chest MRI offered good images of the chest wall deformities with no radiation exposure, detailing anatomical information such as displacement and rotation of the heart or great vessels anomalies.

CONCLUSION

This study suggests the use of chest MRI in pre operative workup for patients with PE to obtain severity indices (Haller Index and Asymmetry Index avoiding radiation exposure to paediatric patients.

Correlations of adolescent idiopathic scoliosis and pectus excavatum

STUDY DESIGN

Radiologic study of scoliosis in pectus excavatum patients.

OBJECTIVES

To determine the relation between pectus excavatum deformity and adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

AIS may be related to other whole body deformities, but few reports have addressed the relation between chest deformity and scoliosis.

METHODS

A total of 248 patients with a diagnosis of pectus excavatum were enrolled in this study. All study patients underwent whole spine anteroposterior radiographs and chest computed tomography. Severity and type of scoliosis and chest deformity were measured using radiographs, and relations between pectus deformity and AIS were analyzed.

RESULTS

Overall, 56 of the 248 study patients had scoliosis (Cobb angle > 10 degrees)--a prevalence of 22.58%. The incidence of scoliosis was significantly higher in female patients (38.46%) (P = 0.002), and Lenke type 1 predominated in pectus patients (48.2%, P < 0.0001). Mean age was greater in the scoliosis group than in the nonscoliosis group (P < 0.0001), and the asymmetry of pectus deformity was more prominent in the scoliosis group (P = 0.007). However, pectus deformity severity was similar in the 2 groups (P = 0.061). Furthermore, although the scoliosis group showed a higher proportion of female patients (P = 0.002), the severities of chest and spinal deformities were similar in the 2 groups for both sexes (P = 0.314, P = 0.227).

CONCLUSIONS

Pectus excavatum and AIS were found to have a high concomitant incidence. And, the age, sex, and type of disease were significantly different in the scoliosis and pectus excavatum groups. Surgeons should consider these relationships when deciding upon treatment in patients with chest and spinal deformities.

Assessment of psychosocial functioning and its risk factors in children with pectus excavatum

Background

Psychosocial functioning is poor in patients with pectus excavatum (PE). However, a comprehensive understanding of this issue does not exist. The aim of this study was to assess the severity of psychosocial problems as associated with PE, as well as to identify its risk factors.

Methods

A comparative study was performed at the Sichuan Academy of Medical Sciences/Sichuan Provincial People's Hospital in Chengdu, China. Patients age 6 to 16 who admitted to the outpatient department for the evaluation or treatment for PE were included in the study. In addition to parental reports of child psychosocial problems on the Achenbach Child Behavior Checklist (CBCL), parents also filled in other structured questionnaires, including socio-demographic variables, patients' medical and psychological characteristics. The severity of malformation was assessed by CT scan. For comparison, an age- and gender- matched control group was recruited from the general population. The socio-demographic and scores on CBCL were compared between patients and control subjects. Univariate and multivariate analysis were performed to examine risk factors for psychosocial problems in patients.

Results

No statistically significant differences were found with respect to social-demographic variables between children with PE and control subjects. Compared with control subjects, children with PE displayed higher prevalence of psychosocial problems in the different scales of the CBCL questionnaire such as 'withdraw', 'anxious-depressed', 'social problems' and 'total problems'. Both univariate and multivariate analyses suggested that age, severity of malformation, and being teased about PE were significantly associated with patients' psychosocial problems.

Conclusions

The information derived from this study supports the opinion that children with PE have more psychosocial problems than children from the general population. Multiple medical and psychosocial factors were associated with patients' impairment of psychosocial functioning.

The Contribution of the Perichondrium to the Structural Mechanical Behavior of the Costal-Cartilage

The costal-cartilage in the human ribcage is a composite structure consisting of a cartilage substance surrounded by a fibrous, tendonlike perichondrium. Current computational models of the human ribcage represent the costal-cartilage as a homogeneous material, with no consideration for the mechanical contributions of the perichondrium. This study sought to investigate the role of the perichondrium in the structural mechanical behavior of the costal-cartilage. Twenty-two specimens of postmortem human costal-cartilage were subjected to cantileveredlike loading both with the perichondrium intact and with the perichondrium removed. The test method was chosen to approximate the cartilage loading that occurs when a concentrated, posteriorly directed load is applied to the midsternum. The removal of the perichondrium resulted in a statistically significant (two-tailed Student’s t-test, p≤0.05) decrease of approximately 47% (95% C.I. of 35–58%) in the peak anterior-posterior reaction forces generated during the tests. When tested with the perichondrium removed, the specimens also exhibited failure in the cartilage substance in the regions that experienced tension from bending. These results suggest that the perichondrium does contribute significantly to the stiffness and strength of the costal-cartilage structure under this type loading, and should be accounted for in computational models of the thorax and ribcage.

Anatomical, histologic, and genetic characteristics of congenital chest wall deformities

There is a large and diverse group of congenital abnormalities of the thorax that manifest as deformities and/or defects of the anterior chest wall and, depending on the severity and concomitant anomalies, may have cardiopulmonary implications. Pectus excavatum, the most common anterior chest deformity, is characterized by sternal depression with corresponding leftward displacement and rotation of the heart. Pectus carinatum, the second most common, exhibits a variety of chest wall protrusions and very diverse clinical manifestations. The cause of these conditions is thought to be abnormal elongation of the costal cartilages. Collagen, as a major structural component of rib cartilage, is implicated by genetic and histologic analysis. Poland syndrome is a unique unilateral chest/hand deficiency that may include rib defects, pectoral muscle deficit, and syndactyly. Cleft sternum is a rare congenital defect resulting from nonfusion of the sternal halves, which leaves the heart unprotected and requires early surgical intervention.

Pectus excavatum: historical background, clinical picture, preoperative evaluation and criteria for operation

Pectus excavatum is a depression of the sternum and costal cartilages which may present at birth, or more commonly during the teenage growth spurt. Symptoms of lack of endurance, shortness of breath with exercise, or chest pain are frequent. Although pectus excavatum may be a component of some uncommon syndromes, patients usually are healthy. Evaluation should include careful anatomic description with photographs, radiography to demonstrate the depth of the depression, extent of cardiac compression, or displacement, measurement of pulmonary function, and echocardiography to look for mitral valve prolapse (in 15%) or diminished right ventricular volume. Indications for surgical treatment include two or more of the following: a severe, symptomatic deformity; progression of deformity; paradoxical respiratory chest wall motion; computer tomography scan with a pectus index greater than 3.25; cardiac compression/displacement and/or pulmonary compression; pulmonary function studies showing restrictive disease; mitral valve prolapse, bundle branch block, or other cardiac pathology secondary to compression of the heart; or failed previous repair(s). The developmental factors, genetics, and physiologic abnormalities associated with the condition are reviewed.